Applications2u with Citrix Receiver allows a fully virtualized desktop experience, and/or allows only Windows-compatible applications to be accessed. The apps-only experience is A2U's secret sauce (a version of XenApp is also offered by ICCGH that provides a similar service), and it's done well. Using the Receiver, remote applications can be launched on a Receiver-launched device, rather than an entire Windows 7-ish desktop. This permits "foreign" applications to run wherever communications and security mandates permit.
Receiver-launched applications could be a simple Excel spreadsheet, an SAP application, something .NET, or whatever might run on the hosted virtual session, in isolation from most of what happens on the client-side environment. The DaaS is in the cloud, or just a cloud-hosted application within A2U construct.
While Applications2u stresses Managed Service Provider (MSP) services, we confined our use and testing to application and hosted virtual desktop use. A2U uses SunGard as its hosting facility. The customer intake process was poised towards setting up extensions of existing resources, but also duplication of internal infrastructure for use as disaster recovery "hot site" use, or other alternate use.
Like other Citrix infrastructure tested, A2U allows resource sharing, local, or A2U-hosted. Like Nivio, the A2U-based storage can be group-shared, we found, as well as policy-enforced (optional) local resource sharing, drives, printers, and the like. In testing, configuration and deployment was fast, and responsiveness was very good. The A2U cloud-hosted sessions were quick, and we were reminded of our Desktone experience.
We did not extensively test hosted applications, and we did not try to pen-test applications hosted via the virtualization provided by the Citrix Receiver application. Apps hosted by A2U have moderate isolation from whatever's going on in the client's hardware and OS environment, but application sessions may be subject to client-side keyloggers or other entrapments that might make them insecure. However, we could find no current CVE notes that portend that Microsoft Office applications are remotely exploitable when hosted elsewhere from a virtualized access. Only the client host, via Citrix Receiver, receives an infection vector. Applications virtualized by A2U aren't necessarily immune from BYOD connection malware. Communications to A2U hosted components were fast, and logon to A2U resources was equally fast.
Applications can be placed in user desktop menus like other applications, and only possible latencies betray the remote execution of the application.